Hello to every members. I have a 1991 300 CE that I really enjoy a lot. I've made some changes in upgrading it's looks and kept engine original, except for changing air filter to a cone filter. Here is my problem lately, Each time the car goes into an upward road , the engine runs rough and stalls after. I would either pull it on the side of the road or if engine complete stalls, I have no other choice but to wait in place and sometimes block traffic for about 15 minutes and it would start again.. So, I decided to take a different route when the car started again and took the city route that was all flat road, since almost all exits from the freeway are all upwards. When I avoided the freeway going back and just took roads that were just leveled roads with no inclines, the car run great with no roughness on my engine. I already did the process of elimination. First, I went through You Tube and did some research and what I got out of my research was that it could be the ignition module. With this part being costly for a brand new part. So, I ended trying a used one from Ebay which lasted for a year with no problem regarding stalling. After a year, the stalling started again when driving into an exit upward road from the freeway. I kept the car garage all the time since I owned it in 2007 and the body and interior is still in perfect condition. I then replaced the ignition coil, fuel pumps, fuel filter and crankshaft sensor. Still having the same problem. Please keep in mind that when I first replaced the ignition module the first time, I had no problem for a year. Anyone out there have any advise? Please help me as I really would love to keep this car. Thank you in advance for any advise in the future.